Method of producing pure iron by electrolysis



Patented Feb. 13, 1923.

onrrao STATES PATENT orrica.

AUGUST scnwmrn, or FRANKFORT-ON-THE-MAIN, GERMANY, as'sronon TO THEFIRM: CHEMISCHE FABRIK GRIESHEIM-ELEKTRON of FRANKFORT-ON-THE- MAIN,GERMANY.

METHOD OF PRODUCING PURE IRON BY ELECTROLYSIS.

No Drawing.

T 0 all 1071 0122. it may concern:

Be it known that I, Aoeus'r Sonwm'ru, a

citizen of Germany, residing at 1*rankfort-.

on-the-Main, Germany, have invented certain new and useful Improvementsin Methods of Producing Pure Iron by lllectrolysis, of which thefollowing is a specification.

My invention refers to the production of pure iron by electrolysis, moreespecially from solutions of ferrous chlorides, and its 4 particularobject is to improve the methods hitherto employed to this end.

It is old to produce pure iron by electrolysis from a pure solution offerrous chloride at a temperature of 70 C. However, this method is of novalue from a. technical point of View inasmuch as it is impossible toobtain a commercial product from the neutral vigorously stirredelectrolyte. Soon after the process is started precipitates containingoxide will settle down.

It has further been proposed to employ as electrolytes neutral ironsalts to which slightly dissociated inorganic or organic acids, such asboric acid, acetic acid, citric acid, carbonic acid or the like havebeen added. All these methods, howeve'r,-yield a very impure iron owingto the fact that along with it carbon, sulphur and phosphorous separateout from the electrolyte and from the anodic iron.

It has further been proposed to add ammonium salts to the iron saltsolutions, but in the products obtained with this method an ironcontaining nitrogen is obtained.

Up till now a pure iron containing not more than 0.03% impurities hasonly been produced from iron solutions acidulated with highlydissociated acids such as hydro-- chloric acid or sulphuric acid, Thus avery superior product as far as purity is concerned, is obtained fromthe solutions of hygroscopic ferrous chloride double salts such as FeCl(la'Cl FeCl .NaCl. However, owing to the addition of sodium chloride,calcium chloride and the like, this process involves great technicaldrawbacks, inasmuch as these additions greatly diminish the solubilityof the ferrous chloride and therefore render it very diflicult to 01tain 1922. Serial No. 564,929.

trolyte containing the highest possible concentration of iron ions.Further drawbacks connected with this process are-caused by the factthat the composition of the electrolyte IS materially changed by theiron of the anode being dissolved, that the percentage of sulphur,phosphorus and manganese in the electrolyte resulting from the ironanode is almost saturated, the temperature being kept at 85 C. andabove.

If these conditions are observed, iron plates of the greatest purity andany desired thickness are obtained.

I-wish it to be understood that I do not desire to be limited to theexact proportions and temperatures mentioned above as many obviousmodifications will occure to a person skilled in the art.

I claim:

1. The process of producing pure iron by electrolysis, consisting-incausing an electric current'to act on a slightly-acidulated solution offerrous chloride ata. temperature of not less than 85 C.

y 2. The process of producing pure iron by electrolysis, consisting incausing an electric current to act on a hot, slightly acidulatedsubstantially saturated solution of ferrous chloride.

3. The process of producing pure iron by electrolysis which consists incausing an elec' tric current to act on a hot solution of ferrouschloride containing a small quantity of free hydrochloric acid rangingbetween onetenth and one-thousandth normal.

In testimony whereof I aflix my signature.

